Sink



FIG. 1 is a perspective view of the sink;

FIG. 2 is a top plan view of the sink;

FIG. 3 is a bottom view of the sink;

FIG. 4 is a front view of the sink;

FIG. 5 is a rear view of the sink;

FIG. 6 is a left side view of the sink; and,

FIG. 7 is a right side view of the sink. 

The ornamental design for a “sink,” as shown and described. 